Pattern Matching Records in SML

records.sml

(* Pattern Matching in Records

Let us pattern match {first:string,second:string,third:string}
*)

(*You should not code like this.
This code will produce a type of val test = fn : {a:'a, b:'b, c:'c} -> {first:'a, second:'b, third:'c}
So, it creates actually records with fields of a, b and c. This is not what you want.
*)
fun test e =
    case e of
        {a,b,c} => {first=a,second=b,third=c}

(*Instead you should code like this*)
fun test1 e =
    case e of
        {first=a,second=b,third=c} => {first=a,second=b,third=c}

Thanks,it's helpful :)

Thanks!